Liquid crystal display device

ABSTRACT

A first substrate includes a first insulating substrate. A first organic insulating film is arranged on the first substrate in a circumference area outside an active area. The first organic insulating film includes a first surface and a first concave portion in the circumference area. A second substrate includes a second insulating substrate. A circumference color filter is laminated on a circumference shield layer and includes a second concave portion arranged facing the first concave portion. The second concave portion spreads toward the first substrate. A second organic insulating film covers the circumference color filter and includes a second surface and a third concave portion covering the second concave portion. A seal material is arranged between the first surface and the second surface, and between the first concave portion and the third concave portion to attach the first substrate and the second substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2013-72230, filed Mar. 29, 2013,the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a liquid crystaldisplay device.

BACKGROUND

Liquid crystal display devices are widely used as typical displaydevices for various kinds of equipments. The liquid crystal displaypanel holding a liquid crystal layer between an array substrate and acounter substrate is manufactured using a large-sized mother substrate.That is, after manufacturing a plurality of liquid crystal displaypanels collectively, each liquid crystal display panel is obtained bycutting the mother substrate.

In recent years, a frame portion of the liquid crystal display panel,i.e., the width between an active area and a panel end tends to becomenarrow. More demand for the narrow frame is growing, more variations oflocation and width of a seal material to attach the array substrate andthe counter substrate are resulted due to bad accuracy of the sealmaterial formation, and also variation of distance between a cut line ofthe mother substrate and an outer end of the seal material is easilyresulted. For this reason, there is a possibility that variation incutting accuracy may be caused due to the variation generated in theseal material.

On the other hand, technology which arranges a black seal material isproposed so that the seal material is shared with the adjacent liquidcrystal display panels in the mother substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute aportion of the specification, illustrate embodiments of the invention,and together with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a plan view schematically showing a display panel PNLapplicable to the liquid crystal display device according to anembodiment.

FIG. 2 is a cross-sectional view schematically showing a structure in acircumference area PRP of the display panel PNL taken along line A-Bshown in FIG. 1.

FIG. 3 is a view showing a layout of a seal material SE, a first spacerSP1 and a second spacer SP2 in the display panel PNL according to theembodiment.

FIG. 4 is a plan view schematically showing a layout of a circumferencecolor filter 22 according to the embodiment.

DETAILED DESCRIPTION

A liquid crystal display device according to an exemplary embodiment ofthe present invention will now be described with reference to theaccompanying drawings wherein the same or like reference numeralsdesignate the same or corresponding portion s throughout the severalviews.

According to one embodiment, a liquid crystal display device includes: afirst substrate including; a first insulating substrate, and a firstorganic insulating film arranged in a circumference area outside anactive area for displaying images, the first organic insulating filmincluding a first surface and a first concave portion in thecircumference area, a second substrate including; a second insulatingsubstrate, a circumference shield layer arranged on the secondinsulating substrate facing the first substrate in the circumferencearea, a circumference color filter laminated on the circumference shieldlayer in the circumference area and including a second concave portionarranged facing the first concave portion, the second concave portionpenetrating to the circumference shield layer and spreading toward thefirst substrate, and a second organic insulating film covering thecircumference color filter and including a second surface and a thirdconcave portion covering the second concave portion in the circumferencearea, a seal material arranged between the first surface and the secondsurface and between the first concave portion and the third concaveportion to attach the first substrate and the second substrate, and aliquid crystal layer held inside surrounded with the seal materialbetween the first substrate and the second substrate.

According to other embodiment, a liquid crystal display device includes:a first substrate including; a first insulating substrate, and a firstorganic insulating film arranged in an circumference area outside anactive area for displaying images, the first organic insulating filmincluding a first surface and a first concave portion in thecircumference area, a second substrate including; a second insulatingsubstrate, a circumference shield layer arranged on the secondinsulating substrate facing the first substrate in the circumferencearea, a circumference color filter laminated on the circumference shieldlayer and including a second a concave portion arranged facing the firstconcave portion, the second concave portion penetrating to thecircumference shield layer and spreading toward the first substrate, anda second organic insulating film covering the circumference color filterand including a second surface and a third concave portion covering thesecond concave portion in the circumference area, a seal materialarranged between the first surface and the second surface, and betweenthe first concave portion and the third concave portion to attach thefirst substrate and the second substrate; and a liquid crystal layerheld inside surrounded with the seal material between the firstsubstrate and the second substrate, wherein the seal material extends toa position in which a first end portion of the first insulatingsubstrate overlaps with a second end portion of the second substrate,the liquid crystal display device further comprises a spacer arrangedbetween the first surface and the second surface in a position in whichthe first end portion of the first insulating substrate overlaps withthe second end portion of the second substrate, the spacer linearlyextends along the position in which the first end portion overlaps withthe second end portion, and the seal material is arranged between thefirst surface and the spacer or between the second surface and thespacer.

FIG. 1 is a plan view schematically showing a display panel PNLapplicable to the liquid crystal display device according to anembodiment of the present invention.

The display panel PNL is formed of an active-matrix type liquid crystaldisplay panel, and equipped with a liquid crystal layer LQ held betweenan array substrate AR and a counter substrate CT facing the arraysubstrate AR. The array substrate AR and the counter substrate CT arepasted together by a seal material SE while a predetermined cell gap isformed between the substrates. The cell gap is formed of pillar-shapedspacers formed in the array substrate AR or the counter substrate CT.The liquid crystal layer LQ is held in the cell gap between the arraysubstrate AR and the counter substrate CT on the inner side surroundedby the seal material SE. The display panel PNL is equipped with anactive area ACT which displays a picture on the inner side surrounded bythe seal material SE. The active area ACT is formed of an approximatelyrectangular shape, and formed of a plurality of pixels PX arranged inthe shape of a matrix, for example.

The array substrate AR is equipped with a gate line G extending in afirst direction X, a source line S extending in a second direction Y soas to cross the gate line G, a switching element SW connected with thegate line G and the source line S, a pixel electrode PE connected withthe switching element SW, etc. Although the counter substrate CT isequipped with a counter electrode CE facing each of the pixel electrodesPE through the liquid crystal layer LQ, for example, the array substrateAR may be equipped with the counter electrode CE.

In addition, explanation is omitted about the detailed structure of thedisplay panel PNL. In the modes such as TN (Twisted Nematic) mode, OCB(Optically Compensated Bend) mode, and VA (Vertical Aligned) mode whichmainly use vertical electric field, while the array substrate AR isequipped with the pixel electrode PE, the counter substrate CT isequipped with the counter electrode CE. Moreover, the array substrate ARis equipped with the both of the pixel electrode PE and the counterelectrode CE in the modes which mainly use lateral electric field, suchas IPS (In-Plane Switching) mode and FFS (Fringe Field Switching) mode.

A signal source necessary to drive the display panels PNL, such as adriving IC chip 2 and a flexible printed circuit (FPC) substrate 3, ismounted in a circumference area PRP outside the active area ACT. In thisembodiment, the driving IC chip 2 and the FPC substrate 3 are mounted ina mounting portion MT of the array substrate AR which extends to outsidea substrate end CTE of the counter substrate CT. The circumference areaPRP is an area surrounding the active area ACT, and formed in the shapeof a rectangular frame including an area in which the seal material SEis arranged. In addition, the illustrated display panel PNL is formed ina square form. In three sides except the mounting portion MT, substrateends of the array substrate AR and substrate ends of the countersubstrate CT overlap each other, and form panel ends. The seal materialextends up to the panel ends of the three sides except the mountingportion MT.

FIG. 2 is a cross-sectional view schematically showing a structure in acircumference area PRP of the display panel PNL taken along line A-Bshown in FIG. 1.

The Array substrate AR is formed using a transparent first insulatingsubstrates 10, such as a glass substrate and a resin substrate. Thearray substrate AR is equipped with a circumference wiring which is notshown and a first organic insulating film 11, etc., in the circumferencearea PRP. In addition, although not illustrated, the array substrate ARis equipped with the switching element, the pixel electrode, thealignment film, etc, in the active area ACT on the first insulatingsubstrate 10 facing the counter substrate CT. Moreover, in thecircumference area PRP, other insulating films may be arranged betweenthe first insulating substrate 10 and the first organic insulating film11.

The first organic insulating film 11 extends not only to thecircumference area PRP but the active area ACT. In the circumferencearea PRP, the first organic insulating film 11 includes a first segment11A on a side close to the active area ACT and a second segment 11B on aside close to a substrate end 10E of the array substrate AR. The secondsegment 11B extends up to the substrate end 10E. In the illustratedexample, a first concave portion 11C is formed between the first segment11A and the second segment 11B in the first organic insulating film 11.The first segment 11A and the second segment 11B face the countersubstrate CT, respectively, and include a first substantially flatsurface 11S, respectively. The first concave portion 11C has a depthpenetrating to the first insulating substrate 10, for example. Theorganic insulating film 11 is formed, for example, of a transparentresin material.

On the other hand, the counter substrate CT is formed using atransparent second insulating substrate 20, such as the glass substrateand the resin substrate. The counter substrate CT is equipped with acircumference shield layer 21, a circumference color filter 22, a secondorganic insulating film 23, etc., in the circumference area PRP on thesecond insulating substrate 20 so as to face the array substrate AR. Inaddition, although not illustrated, the counter substrate CT is equippedwith a black matrix, a color filter layer, an alignment film, etc. inthe active area ACT.

The circumference shield layer 21 is formed on the second insulatingsubstrate 20 facing the array substrate AR, and extends to substantiallywhole area of the circumference area PRP. That is, the circumferenceshield layer 21 is located in respective above portions of the firstsegment 11A, the second segment 11B, and the first concave portion 11C,and formed continuously without breaking off up to a substrate end 20Eof the counter substrate CT. The circumference shield layer 21 has aconstant film thickness. Moreover, the circumference shield layer 21 isformed with the same material as the black matrix in the active areaACT, and connected with the black matrix. The circumference shield layer21 is formed of the resin material colored in black or light shieldingmetal material such as chromium (Cr), etc.

The circumference color filter 22 is laminated on the circumferenceshield layer 21. In the circumference area PRP, the circumference colorfilter 22 includes a second segment 22B on a side close to the substrateend 20E while including a first segment 22A on a side close to theactive area ACT. The second segment 22B extends up to the substrate end20E. In the illustrated example, a second concave portion 22C is formedbetween the first segment 22A and the second segment 22B in thecircumference color filter 22. The second concave portion 22C has adepth penetrating to the circumference shield layer 21, for example. Thesecond concave portion 22C is formed in a position which counters withthe first concave portion 11C. The second concave portion 22C is formedso that the second concave portion 22C gradually spreads from a portionpenetrating up to the circumference shield layer 21 toward the arraysubstrate AR. That is, the second concave portion 22C is formed betweena slope face 22AS located at an end of the first segment 22A, and aslope face 22BS located at an end of the second segment 22B.

The second organic insulating film 23 extends to not only thecircumference area PRP but the active area ACT. In the circumferencearea PRP, the second organic insulating film 23 covers the secondconcave portion 22C while covering the circumference color filter 22.That is, the second organic insulating film 23 covers the circumferenceshield layer 21 exposed by the second concave portion 22C while beinglaminated on the first segment 22A and the second segment 22B. In theillustrated example, a third concave portion 23C is formed in a positionwhich covers the second concave portion 22C in the second organicinsulating film 23. The second organic insulating film 23 laminated onthe first segment 22A and the second segment 22B includes a secondsubstantially flat surface 23S. The second surface 23S counters a firstsurface 11S. If its attention is paid to the third concave portion 23C,the third concave portion 23C is formed so that the third concaveportion 23C gradually spreads from its bottom portion toward the arraysubstrate AR. That is, the third concave portion 23C is formed between agentle slope face 23AS which covers the slope face 22AS and a gentleslope face 23BS which covers the slope face 22BS. The slope face 23ASand slope face 23BS incline toward the bottom of the third concaveportion 23C from the second surface 23S. The second organic insulatingfilm 23 is formed of a transparent resin material, for example.

The display panel PNL is further equipped with a first spacer SP1 and asecond spacer SP2 in the circumference area PRP. Each of the firstspacer SP1 and second spacer SP2 is arranged between the first surface11S and the second surface 23S. The first spacer SP1 is located on aside close to the active area ACT, and the second spacer SP2 is locatedon the substrate ends 10E, 20E side. In the illustrated example, thefirst spacer SP1 and second spacer SP2 are formed in the array substrateAR. Precisely, the first spacer SP1 and second spacer SP2 are formed onthe first surface 11S of the first organic insulating film 11 in theshape of taping off toward the counter substrate CT. A tip portion ofthe first spacer SP1 touches to the second surface 23S. The tip portionof the second spacer SP2 is apart from the second surface 23S. Inaddition, the counter substrate CT may be equipped with each of thefirst spacer SP1 and the second spacer SP2. In this case, they areformed on the second surface of the second organic insulating film 23,and formed in the shape of tapering off toward the array substrate AR.

The seal material SE which attaches the array substrate AR and thecounter substrate CT are filled between the first surface 11S and thesecond surface 23S. Moreover, the seal material SE is filled in thefirst concave portion 11C and the third concave portion 23C.Furthermore, the seal material SE is filled between the second spacerSP2 and the second surface 23S, and extends up to the position in whichthe substrate end 10E and the substrate end 20E overlap each other. Thefirst spacer SP1 is surrounded with the seal material SE.

The liquid crystal layer LQ is enclosed inside the seal material SE(active area side).

FIG. 3 is a view showing a layout of the seal material SE, the firstspacer SP 1 and the second spacer SP2 in the display panel PNL accordingto the embodiment. Here, only the principal portion required forexplanation is illustrated.

The seal material SE extends up to the substrate end 10E in the threesides of the array substrate AR except the mounting portion MT. Thefirst spacer SP1 is located inside the seal material SE, and formed inthe shape of a dot. Although the illustrated example shows the casewhere the first spacer SP1 is formed in two lines, the layout of firstspacer SP1 is not restrict to this example. In the three sides exceptthe mounting portion MT, the second spacer SP2 is formed in the shape ofa straight line along the substrate end 10E. Although the illustratedexample shows the case where the second spacer SP2 is formed in theshape of a rectangular frame which continuously extends, the form of thesecond spacer SP2 is not restricted to this example.

FIG. 4 is a plan view schematically showing a layout of thecircumference color filter 22 according to the embodiment. Here, onlythe principal portion required for explanation is illustrated.

In this embodiment, the first segment 22A and the second segment 22B ofthe circumference color filter 22 are formed in the shape of a straightline extending in the first direction X and the second direction Y. Thefirst segment 22A is formed in the shape of a rectangular framesurrounding the rectangular active area ACT. The second segment 22B islocated in the outside of the first segment 22A so as to sandwich thesecond concave portion 22C with the first segment 22A. The secondsegment 22B is located in the outermost circumference (panel end) of thedisplay panel PNL. In addition, although not illustrated, the firstspacers SP1 in the shape of a dot are dotted in a position whichoverlaps with the first segment 22A. Moreover, the second spacer SP2 inthe straight line shape is formed in a position which overlaps with thesecond segment 22B. In this embodiment, although the first segment 22Aand the second segment 22B are formed in the shape of a frame formedcontinuously, respectively, they may break off on the way.

The color filter arranged in the active area ACT is formed of a redcolor filter CFR arranged corresponding to a red pixel, a green colorfilter CFG arranged corresponding to a green pixel and a blue colorfilter CFB arranged corresponding to a blue pixel. The color filters areformed of the resin material colored in red, green, blue, etc.,respectively. The above-mentioned circumference color filter 22 isformed with the same material as one of the color filter layers arrangedin the active area ACT. In this embodiment, the circumference colorfilter 22 is formed with the same material as the blue color filter CFB,for example.

Next, an example of a manufacturing method of the above-mentioneddisplay panel PNL is explained briefly.

First, the first mother substrate which collectively forms a pluralityof array substrates AR is prepared. The first mother substrate is formedusing an insulating substrate which becomes the first insulatingsubstrate, and equipped with various wirings, such as the gate line, thesource line, the switching element, etc., various insulating films suchas the organic insulating film, the pixel electrode, the alignment film,the first spacer, the second spacer, etc.

On the other hand, the second mother substrate which collectively formsa plurality of counter substrates CT is prepared. The second mothersubstrate is formed using the insulating substrate which becomes thesecond insulating substrate, and equipped with the black matrix, thecircumference shield layer, the circumference color filter, the colorfilter layer, the second organic insulating film, the alignment film,etc.

Then, after arranging the seal material on the first mother substrate orthe second mother substrate so that the seal material surrounds theactive area respectively, the liquid crystal material is dropped on theinner side surrounded with the seal material. Successively, the firstmother substrate and the second mother substrate are attached together.

Then, the display panel PNL is taken out from a pair of mothersubstrates in which the liquid crystal layer is held between the firstmother substrate and the second mother substrate. In this process, theboth of the first mother substrate and the second mother substrate arecut along cutting lines, respectively. Thereby, the display panel PNLholding the liquid crystal layer LQ between the array substrate AR andthe counter substrate CT is manufactured.

According to this embodiment, in the region in which the seal materialSE is arranged, the first concave portion 11C is formed in the arraysubstrate AR. The third concave portion 23C is formed in the regionwhich counters the first concave portion 11C in the counter substrateCT. Especially, the third concave portion 23C has a form which spreadsas the third concave portion 23C goes to the array substrate AR from itsbottom side, and is specified between the gently inclined slope faces23AS and 23BS. For this reason, since the seal material SE spreads alongthe gentle slope faces 23AS and 23BS toward the substrate ends 10E and20E when the seal material SE spreads in a width direction, it becomespossible to reduce resistance at the spreading time of the seal materialSE. Therefore, the seal material SE easily spreads up to the substrateends 10E and 20E.

In recent years, the demand for the narrow frame with a short distancebetween the active area ACT and the substrate ends 10E and 20E isincreasing. For this reason, although we are anxious about the variationin the cutting accuracy resulting from formation accuracy of the sealmaterial SE, since the spreading resistance of the seal material SE isreduced, the seal material SE easily spreads up to the substrate ends10E and 20E. Thereby, it becomes possible to reduce the variation in theformation accuracy of the seal material SE, and to reduce the variationin the cutting accuracy resulting from the formation accuracy of theseal material SE. Accordingly, it becomes possible to control the fallof the manufacturing yield.

Moreover, since the seal material SE is filled up not only between thefirst surface 11S of the first organic insulating film 11 and the secondsurface 23S of the second organic insulating film 23 but also betweenthe first concave portion 11C and the third concave portion 23C, itbecomes possible to increase the amount of the applied seal material SE.Further, it becomes possible to increase the areas of the arraysubstrate and the counter substrate, in which the seal material SEcontacts the substrates, respectively. For this reason, it becomespossible to improve adhesive strength to attach the array substrate ARand the counter substrate CT by the seal material SE.

As explained above, according to the embodiment, the liquid crystaldisplay device which can control fall of manufacturing yield can besupplied.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. In practice, the structural and method elementscan be modified without departing from the spirit of the invention.Various embodiments can be made by properly combining the structural andmethod elements disclosed in the embodiments. For example, somestructural and method elements may be omitted from all the structuraland method elements disclosed in the embodiments. Furthermore, thestructural and method elements in different embodiments may properly becombined. The accompanying claims and their equivalents are intended tocover such forms or modifications as would fall with the scope of theinventions.

What is claimed is:
 1. A liquid crystal display device, comprising: afirst substrate including; a first insulating substrate, and a firstorganic insulating film arranged in a circumference area outside anactive area for displaying images, the first organic insulating filmincluding a first surface and a first concave portion in thecircumference area, a second substrate including; a second insulatingsubstrate, a circumference shield layer arranged on the secondinsulating substrate facing the first substrate in the circumferencearea, a circumference color filter laminated on the circumference shieldlayer in the circumference area and including a second concave portionarranged facing the first concave portion, the second concave portionpenetrating to the circumference shield layer and spreading toward thefirst substrate, and a second organic insulating film covering thecircumference color filter and including a second surface and a thirdconcave portion covering the second concave portion in the circumferencearea, a seal material arranged between the first surface and the secondsurface and between the first concave portion and the third concaveportion to attach the first substrate and the second substrate, and aliquid crystal layer held inside surrounded with the seal materialbetween the first substrate and the second substrate.
 2. The liquidcrystal display device according to claim 1, wherein the seal materialextends to a position in which a first end portion of the firstinsulating substrate overlaps with a second end portion of the secondsubstrate.
 3. The liquid crystal display device according to claim 1,further comprising a spacer arranged between the first surface and thesecond surface in a position in which a first end portion of the firstinsulating substrate overlaps with a second end portion of the secondsubstrate.
 4. The liquid crystal display device according to claim 3,wherein the spacer linearly extends along the position in which thefirst end portion overlaps with the second end portion.
 5. The liquidcrystal display device according to claim 3, wherein the seal materialis arranged between the first surface and the spacer or between thesecond surface and the spacer.
 6. The liquid crystal display deviceaccording to claim 1, wherein the first and second organic insulatingfilms are formed of transparent resin material.
 7. A liquid crystaldisplay device, comprising: a first substrate including; a firstinsulating substrate, and a first organic insulating film arranged in ancircumference area outside an active area for displaying images, thefirst organic insulating film including a first surface and a firstconcave portion in the circumference area, a second substrate including;a second insulating substrate, a circumference shield layer arranged onthe second insulating substrate facing the first substrate in thecircumference area, a circumference color filter laminated on thecircumference shield layer and including a second concave portionarranged facing the first concave portion, the second concave portionpenetrating to the circumference shield layer and spreading toward thefirst substrate, and a second organic insulating film covering thecircumference color filter and including a second surface and a thirdconcave portion covering the second concave portion in the circumferencearea, a seal material arranged between the first surface and the secondsurface, and between the first concave portion and the third concaveportion to attach the first substrate and the second substrate; and aliquid crystal layer held inside surrounded with the seal materialbetween the first substrate and the second substrate, wherein the sealmaterial extends to a position in which a first end portion of the firstinsulating substrate overlaps with a second end portion of the secondsubstrate, the liquid crystal display device further comprises a spacerarranged between the first surface and the second surface in a positionin which the first end portion of the first insulating substrateoverlaps with the second end portion of the second substrate, the spacerlinearly extends along the position in which the first end portionoverlaps with the second end portion, and the seal material is arrangedbetween the first surface and the spacer or between the second surfaceand the spacer.
 8. The liquid crystal display device according to claim7, wherein the first substrate includes a mounting portion arranged atone end of the first insulating substrate for mounting a drivingcircuit.
 9. The liquid crystal display device according to claim 7,wherein the second and third concave portions include a slope surfacespreading toward the first insulating substrate, respectively.
 10. Theliquid crystal display device according to claim 7, wherein the firstand second organic insulating films are formed of transparent resinmaterial.